Antihalation film



Aug- 3, 1943 G. F. NADEAU ETAL ANTIHALATION FILM Filed Jan. 14, 1942 NT/HALAT/ON LAYER 0F AM/NE A/fred 0.. 5/ 5 60/e E/laaeau a INVENT BY y K L2 y ATTORNEYS Patented Aug. 3, 1943 'ANTIHAIlATION FILM Gale F. Nadeau and Alfred n. Slack, Rochester,

N. Y., assi'gnors to Eastman Kodak Company, Rochester, N. Y. a corporation of New Jersey Application- January 14, 1942, Serial No. 426,738

5 Claims.

This invention relates to photographic film, and more particularly to photographic film protected against halation.

This invention is in part a continuation of the Nadeau and Slack U. S. Patent,- 2,289,799, granted July 14, 1942 and U. S. Patent 2,311,073, granted February 16, 1943.

Antihalation coatings, for the protection of sensitive photographic film against halation, of the type removable in photographic processing solutions are well known. Antihalation coatings of the type not removable in photographic processing solutions, but which are intended to be retained, minus the antihalation dye, are less well known. Such coatings are described in the prior applications above cited.

One problem in connection with backings of the latter type after adequate measures have been taken to prevent base staining by the antihalation dyes, is to prevent the deposition of dye particles on the surface of the backing of such.

nature and distribution that when film is wound on a spool these particles under the influence of moisture transfer to the emulsion layer in contact therewith. This problem, not solved upto the time of the present invention, has required in many cases, the dispersion of th antihalatlon dye in the film support itself from which it is, of course, not removable or decolorlzable with ease. Even when such desirable water-swellable coatings as those described in the prior applications cited, are used, the control of the balance between the bleachability of the dye and its tendency to bleed in water is very critical.

We have found that these defects can be elimmated by converting the dye and its carrier material to a less water-soluble salt through the use of amines slightly soluble or insoluble in water. The function of the amine is to react with the acid group of the carrier and make a less water-susceptible compound than the free acid form of the carrier. Also, the dyes, normally sulfonic acid derivatives, posssess considerable water-solubility and, by their conversion to amine salts, this solubility in water is very layer I l and on the opposite side with the antihalation layer l2 of the invention, of an amine salt of a cellulose mixed organic acid ester insoL uble in photographic processing solutions e. g. cellulose acetate phthlate of the composition described'in the prior U. S. patent application, Serial No. 381,695, above cited, containing sub:

' stantially four to eight acyl groups per C24 cellulose unit, of which not more than one is a dicarboxylic acid acyl group and the remainder are aliphatic monobasic acid acyl groups of less than five carbon atoms, and an amine salt of an acid dye.

Other cellulose mixed organic acid dicarboxylic acid esters may be used, such as those containing substantially four to eight acyl groups. per C24 cellulose unit, of which not more than one is a dicarboxylic acid acyl group and the remuch decreased, if not eliminated altogether.-

The amine salt of the dye possesses an additional advantage in that it is usually much more solvent-soluble than the free acid form of the dye.

The figure of the accompanying drawing shows in cross-sectional view a sensitive photographic film constructed in the manner of our invention.

As shown therein thesupport I 0 of a cellulose ester or other material such as a synthetic resin,

is provided on one side witha sensitive emulsion mainder are aliphatic monobasic acid acyl groups, e. g. cellulose valerate phthalate, caprylate succinate, etc.

The following examples typify the operation of the invention, however, they are given merely for illustration and are intended in no way to limit the scope of the invention.

EXAMPLE 1 Per cent Cellulose acetate phthalate (27% acetyl,

13% phthalyl) 1 4 Dicyclohexylamine 1.65 Aerosol AY (sodium sulfodiamyl succinate) 1 Acetone r 45 Methyl Cellosolve 20 Ethyl alcohol 28.35

Over this layer may be applied a dye solution of the following composition:

or dye 1.35:. m-Toluidinea 2.0 Ethyl alcohol 96.65

. (Muehler U. S. Patent No. 2,150,695; granted March 14, 1939). The numbers following the 4 Per cent names of the dyes refer to the Schultz Dyestufl Tables 7th edition (1931). tive dyes of the acid type photographic processing solutions. If desired, commercial Brilliant Green 131; (guanidine salt of Acid Green) may be used in alcoholic solution for dyeing the backing layers.

, aw 2 v Supports of the type described in Example 1 may be coated with an amine salt of a cellulose dicarboxylic'acid ester from a solution of the following composition:

Cellulose acetate phthalate (27% acetyl, 13% phthalyl) m-Toluidine 2.5 Aerosol AY 1 Ar'pfnnp 45 Methyl Cellosolve 20 Ethyl alcoh 26.5

Any of the following solutions may be used for dyeing this layer.

The dye designated as "A dye in solutions A, Band C, may be a sulfonated Malachite Green dye, and 3" dye may be Acid Magenta.

In addition to the amines shown in the above formulas we may use many other organic amines such as dioctyl amine, tributyi amine, diamyl amine, guanidine, etc. purpose of our invention whfle all amines appear to be eifective to a certain extent in accomplishing the objects of the invention, the amines chosen. should transform the antihalation dye and carrier material to compounds possessing reduced moisture susceptibility. It is for this reason that amines possessing a minimum solubility in water are particularly useful.

It is to be understood that the disclosure herein is by way of example, and that we consider as dicyclohexyl amine, aniline, diphenyl In choosing an amine for the These dyes are fugiwhich readily form salts with amines and which are bleachable in I 9,856,055 included in our lnyention all modifications and equivalents falling within the scope of the ap- Pended claims.

amine salts of dyes such as Luxol what we claim is: l. A photographic film free from halation which comprises a support provided on one side thereof with a light sensitive emulsion layer, and

l on the opposite side with a layer containing a Per cent I it should be noted that cellulose mixed organic acid dicarboxylic acid ester containing substantially four to eight aliphatic monobasic organic acid acyl and dicarboxylic acid acyl groups per C24 cellulose unit of which not more than one is a dicarboxylic acid group and the remainder are aliphatic monobasic acid acyl groups, and a mixture of an organic amine and an acid dye.

. 2. A photographic film free from halation which comprises a support provided on one side thereof with a light sensitive emulsion layer, and on the opposite side with a layer containing an amine salt of a cellulose mixed organic acid dicaiborwlic acid ester containing substantially four to eight aliphatic monobasic organic acid acyl and dicarboxylic acid acyl groups per C24 cellulose unit of which not more than one is a dicarboxylic acid group and the remainder are aliphatic monobasic acid acyl groups, and an amine salt of an acid dye.

3. A photographic film free from halation which comprises a support provided on one side thereof with a light sensitive emulsion layer, and on the opposite side with a layer containing a cellulose mixed organic acid dicarboxylic acid ester cotaining substantially four aliphatic monobasic organic acid acyl and dicarboxylic acid acyl groups per C24 cellulose unit of which not more than one is a dicarboxylic acid acyl group and the remainder are aliphatic monobasic acid acyl groups, and an amine salt of an acid dye.

4. A photographic film free from halation which comprises a support provided on one side thereof with a light sensitive emulsion layer, and on the opposite side with a layer containing an amine salt of a cellulose mixed organic acid dicarboxylic acid ester containing substantially eight aliphatic monobasic organic acid acyl and dicarboxylic acid acyl groups per C24 cellulose unit of which not more than one is a dicarboxyiic acid acyl group and the remainder are aliphatic monobasic acid acyl groups, and an amine salt of an acid dye.

5. A photographic film free from halation which comprises a support provided on one side thereof with a light sensitive emulsion layer, and on the opposite side with a layer containing an amine salt of a cellulose mixed organic acid dicarboxylic acid ester containing substantially four to eight acyl groups per C24 cellulose unit of which one is a dicarboxylic acid acyl group and the remainder are aliphatic monobasic acid acyl groups, and an amine salt of an acid dye.

GALE F. NAlDEAU. ALFRED D. SLACK. 

